Iridium tetroxide

Iridium(VIII) oxide
Names
	IUPAC name Iridium(VIII) oxide
Identifiers
CAS Number	474103-25-8;
3D model (JSmol)	Interactive image;
	InChI InChI=1S/Ir.4O Key: WIFDYPVIKSJTTM-UHFFFAOYSA-N;
	SMILES O=[Ir](=O)(=O)=O;
Properties
Chemical formula	IrO4
Molar mass	256.213 g·mol−1
Melting point	−267.15 °C (−448.87 °F; 6.00 K)
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Iridium tetroxide (IrO₄, Iridium(VIII) oxide) is a binary compound of oxygen and iridium in oxidation state +8.^[1] This compound was formed by photochemical rearrangement of [(η¹-O₂)IrO₂] in solid argon at a temperature of 6 K (−267.15 °C; −448.87 °F). At higher temperatures, the oxide is unstable.^[2] The detection of the iridium tetroxide cation IrO⁺
₄ by infrared photodissociation spectroscopy with formal oxidation state +9 has been reported, the highest currently known of any element.^[3]^[4] However no salts are known, as attempted production of an Ir(IX) salt such as IrO₄SbF₆ did not result in anything.

^ Cite error: The named reference Gong was invoked but never defined (see the help page).
^ Citra, Angelo; Andrew, Lester (1999). "Reactions of Laser-Ablated Iridium Atoms with O₂. Infrared Spectra and DFT Calculations for Iridium Dioxide and Peroxoiridium(VI) Dioxide in Solid Argon". J. Phys. Chem. A. 103 (21): 4182–4190. Bibcode:1999JPCA..103.4182C. doi:10.1021/jp990388o.
^ Cite error: The named reference himmel2010 was invoked but never defined (see the help page).
^ Cite error: The named reference wang2014 was invoked but never defined (see the help page).

[Gong-1] Cite error: The named reference Gong was invoked but never defined (see the help page).

[Citra-2] Citra, Angelo; Andrew, Lester (1999). "Reactions of Laser-Ablated Iridium Atoms with O₂. Infrared Spectra and DFT Calculations for Iridium Dioxide and Peroxoiridium(VI) Dioxide in Solid Argon". J. Phys. Chem. A. 103 (21): 4182–4190. Bibcode:1999JPCA..103.4182C. doi:10.1021/jp990388o.

[himmel2010-3] Cite error: The named reference himmel2010 was invoked but never defined (see the help page).

[wang2014-4] Cite error: The named reference wang2014 was invoked but never defined (see the help page).

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